Moving stairway



MOVING STAIRWAY Original Filed June 26, 1937 Sept. 1o, 1940.

INV ENTOR me n/O/O.

ATT EY j' l wl'rNEssEs;

Patented Sept. 10, `1940 Y UNITED f STATES 2,214,580 MOVIN STAIRIWAYJames Dunlop,

inghouse Electric Elevator Ridgewood, N. J., assignor to West- Company,Chicago,

Ill., arcorporation of Illinois Original application June 26, '1937,Serial No.

150,492. Divided and 30, 1938 Serial N0. 198,8

this application March 6 7 s claims. (ci. 30s- 26) My invention relatesto vmoving stairways and more particularly to the steps embodied thereinand is a division of my applicationv Serial No. 150,492, iiled June 26,1937 and assigned to the Westinghouse Electric Elevator Company.

One object of my invention is to provide a moving stairway step whichshallv be simple and economical to manufacture and which shall be quietand easily maintained in operation under varying conditions. x

A further object is to provide for obtaining quietness in the operationof moving vstairway steps when they are carrying passengers as well aswhen they are not carrying passengers.

A further object is tqprovide for absorbing the vibrations of a movingstairway step in one manner when it is traveling under no load and forabsorbing the vibrations of the step in another manner when it istraveling under a load.

It is also an object to provide for the automatic vtransfer of the stepfrom one vibration preventing means to another vibration preventingmeans when the load condition of the step changes.

For ay better understanding of the invention reference may be had to theaccompanying draw-` ing, in which:

Figure 1 is a top plan view ing stairway;

Fig. 2 is a view in rear elevation, partly in sec- 3'0 tion, of the stepshown in Fig. 1, and the bushings for the axles supporting the step.

' Fig. 3 is a view in right-hand end elevation of the step shown in Fig.1; and

Fig. 4 is an enlarged View, partly in section, of

of a stepf for a mov? '315 one of the resilient bushings mounted on thestep axles for decreasing the vibration of the step.

Referring more particularly to the drawing, I have illustrated a movingstairway step as com-v prising a step tread IIJ, an rapron or riser II,a

pair of end bars I2 and I3, a pair of leading'rollers I4 and I5 and apairfof trailing rollers I6 and l1 l Ill may be constructed of anysuitable material, preferably of molded fibrous material, witha heathardened binder, and it may be constructed in a plurality of sections orin one complete ysection provided with a plurality of cleats I9 disposedon its upper surface to provide a plurality of grooves` 20. 'Ihe treadis supported by vresting its rear 4edge upon the upper edge of the riserIl and its front edge upon an angle iron 22. 'I'he angle iron extendsfrom the end bar I2 to the end bar I3. The underside of the treadisprovided witha groove 23 which re- '.Ihe step tread Ceives the angleiron 22 to prevent the tread from Working forward or backward. The angleiron is supported in position by securing one end to 'a bracket 24 onthe upper portion of the end bar I3 by suitable bolts 25. The other endof the angle `5 iron is secured in a like manner tol a bracket 26 on theupper portion of the end bar I2. The lower ends of the bars i2 and I3are provided with suitable brackets 27 and 28 for supporting the loweredge of the apron I I.

As shown in Figs. 2 and 3, the apron II comprises a sheet 30, preferablyof stainless steel, bent into a slight upward curve and having its upperedge 3I, its lower edge 32 and its end edges 33 bent inwardlysub-stantially at right angles to the face of the riser, 'I'he upperbent-in edge 3I is provided with small upwardly extruded portions 36disposed to enter grooves 3l in the underside of the tread I6 to assistin holding the jtread in its correct position. 20

A tapped bar 38 is spot welded to the underside of the bent in edge 3lto act as a stilening bar and to also provide a plurality of tap holesdisposed to receive a plurality of screws l2 which pass through thetread I3 and hold it in position on the riser II. The inturned loweredge 32 of .the riser is bolted to the cooperating lugs 2'1 and 28 onthe end bars I2 and I3. The inturned edge 32 is also provided withdownwardly extruded portions 48 disposed to be seated in cooperatinggrooves in the brackets 2l and 28, respectively, at the lower ends ofthe bars 'I2 and I3, to aid in maintaining the riser plate in itscorrect position on the end bars.

Referring to the rollers on the step, the lead-A ing roller I4 ismounted upon the outer end of a front axle and is held in positionthereon by a nut 6I. The axle is mounted in an axle support 51 on thefront or upper portion of the end bar I 2 and in an axle support bracket62 attached to the cross angle iron 22 by a bolt 63. The axle is held inthe brackets 5l and 62 by resilient bushings 64, preferably of rubber orsimilar material. A cotter pin is disposed through a collar 66 on theaxle 63 to prevent its movement to the left, and a similar Cotter pin 6land collar 68 are disposed adjacent to the bracket 62 to prevent theaxle from moving to the right. The leading roller I5 at the right ismounted in the same manner as the roller just described. 50

The trailing roller I6 is rotatably mounted upon the outer end of a stubaxle 'lI and is secured thereon by a suitable nut 12. The stub axle ismounted in the trailing axle support 13 by means of afresilient sleeve64a whichis retained in posi- 55 tion by a pair of suitable washers 14and 15. A nut 16 on the inner end of the stub axle holds the combinationfirmly in position. The trailing roller I1 is mounted upon a stub axledisposed in the trailing roller support 18 in the same manner as thestub axle for the trailing roller I6 is mounted in its support.

In the steps heretofore constructed, the resilient bushings Si and ellahave been constructed usually of a solid resilient material, but inpracticing my invention I provide a resilient bushing having twodifferent surfaces for supporting the step in order to decrease itsvibratio-n and enable it to be operated without the noise that usuallyaccompanies moving stairway steps. By referring to Fig. 4, it will beseen that the bushing S4 is provided with a no-load bearing surfacecomprising a pair of narrow circular ridges 8@ and 8l extending entirelyaround the bushing to engage the inner surface of the axle supportbracket in which the bushing is mounted for the purpose of supportingthe step while it is operating without load, The bushing is alsoprovided with a load bearing surface 82 of less diameter than theno-lcad surface and which is disposed to receive and support the axlesupport bracket when the step is carrying a load such as that of apassenger. A groeve B3 is disposed at each side of each of the ridgesSi! and Si to provide room for the ridge of resilient material to spreador iiow into when a load on the step bears the bracket ldownwardly towhere it engages the load bearing surface S2. The bushing is alsoprovided with a beveled end 3b to enable it to be easily positioned inthe bracket during the assembling of the step parts. A shoulder 81 isdisposed on the other end of the bushing to provide a seat for thecollar 6G' through. which the cotter pin 65 passes.

Each axle support bracket is provided with a similar bushing, and itwill be apparent that when the step is running with no load, the ridgesSi) and Sl on each of the bushings will support the bracket on theirthin outer faces and that the tendency for the step to vibrate in adisturbing manner will be eliminated by reason of the light resilientsupport on which it rests. It will also be apparent that when the stepis loaded, as by a passenger standing thereon, the weight of the loadwill cause the bracke-ts to overcome the slight resilient support of theridges 8B and 8l and move down to rest upon the face 82 of the centralportion of the bushing, and that in this position the loaded step willbe firmly but resiliently supported in such manner that practically allvibration because of its loaded condition will be eliminated, and,therefore, that the step will operate quietly and without any disturbingnoise.

Although I have illustrated and described only one moving stairway stepembodying my invention, it will be obvious that many changes andmodifications may be made therein without departing from the spirit andscope of the invention.

I `claim as my invention:

l. A bushing for an axle of a load carrying device comprising acylindrical resilient sleeve having a cylindrical heavy load carryingsurface and a cylindrical light load carrying surface, said light loadcarrying surface having a load bearing surface of less area than theheavy load carrying surface and having a greater diameter than thediameter of the heavy load carrying surface, 'and a groove disposedbetween the heavy load carrying surface and the light load carryingsurface to permit displacement of the light load carrying surface to aposition level with the heavy-load carrying surface when it iscompressed by a heavy load.V

2. A bushing for an axle of a load carrying device comprising acylindrical rubber sleeve having an outer cylindrical heavy loadcarrying surface, a pair of outer cylindrical light load carryingsurfaces of greater diameter and less area than the heavy load carryingsurface, and grooves disposed between the light load carrying surfacesand the heavy load carrying surface to permit displacement of the lightload carrying surfaces when a load thereon exceeds a predeterminedvalue.

3. A moving stairway step having an axle, a tread supporting membermounted on the axle, and a bushing ofresilient'material disposed betweenthe axle and the tread, supporting member, said bushing having a no-loadsurface extending transversely of the axis of the axle for supportingsaid member' when the step has no load and having a load surface of morethan 'twice the area. of the no-load surface forfsupporting said memberwhen the step is loaded.

f 4. A moving stairway step having an axle, a tread supporting membermounted on the axle, and a bushing of resilient material disposed.between the axle and the tread supporting member, said bushing having onits outer surface a. load surface disposed in parallel with andtransversely of the longitudinal axis of the bushing and a noloadsurface of less than one-half the area of the load surface V'to preventthe tread supporting member from. 4engaging the load surface when thestep has no load.

5. A moving stairway step having an axle, a

tread supporting member mounted on the axle,

and a bushing of resilient material disposed between t-he axle and thetread supporting member, said bushinghaving a no-load surface forsupporting the step when it is not loaded, a load surface for supportingthe step when itis loaded, and a groove transverse to the axis of theaxle between theload surface portion and the nolcad surface portion topermit the no-load surface portion to expand therein when it is leveledwith the load surface the step. l

6. A moving stairway step having an axle, a tread supporting member, anda cylindrical bushing of rubber like material disposed `on the axle andconcentric therewith for supporting the tread-supporting member, saidbushing having a load surface of revolution parallel to the axis of theaxle and a no-load ridge of less than half the area of the .load surfaceand of greater ydiameter than .the load surface and having a groovebetween :the load surface and the no-load surface of less diameter thanthe load surface to permit the no-lcad surface portion to expand thereinwhen a load on the step presses the tread supporting member down `intoengagement with the loadsurface. f

7. A moving stairway step comprising a tread member, an axle forcarrying the tread' memby the weight of a load on n ber, and a bushingof rubber-like material disl to be engaged by the tread member when thestep is loaded. y

8. A moving stairway step comprising a tread member, an axle forcarrying the tread member, a bushing disposed between the axle and thetread member, said bushing having a light load section of rubber-likematerial for supporting the tread member when the step is not loaded anda heavy load section of rubber-like material disposed to be out ofengagement with the tread member when the step is not loaded but to beengaged by the tread member when the step is loaded to prevent ametal-to-metal engagement between the tread member and the axle at anytime.

JAMES DUNLOP.

